The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Many vehicles today are equipped with head units that can establish wired or wireless short-range communication links with portable user devices such as smartphones. A user can, for example, direct audio output from her smartphone via the head unit to amplify the sound, or provide voice commands to the head unit to originate a call from the smartphone when driving.
As the number of applications of head unit-to-smartphone connections continues to grow, the risk that an unauthorized device accesses the smartphone by masquerading as a legitimate head unit also increases. For example, an aftermarket vendor of a head unit can clone the identifier of a legitimate, properly authorized head unit. The head unit then can replay the cloned identifier to the smartphone to trick the smartphone into “thinking” that it is connected to an authorized vehicle. Further, some original equipment manufacturers (OEM)s can allocate identifiers sequentially, and aftermarket vendors can cycle through blocks of potentially valid numbers to find an identifier the smartphone accepts.